A rapid procedure for the large scale purification of elastase and cathepsin G from human sputum

Prep Biochem. 1979;9(1):15-31. doi: 10.1080/00327487908061669.


A procedure is described which permits the rapid isolation of large amounts of elastase and cathepsin G from purulent sputum. This procedure involves: (1) digestion of sputum with DNase, (2) extraction of the insoluble residue that remains with 1 M NaCl, pH 8, (3) affinity chromatography on Sepharose-bound Trasylol, and (4) separation of the two enzymes by chromatogrphy on CM-Sephadex. Starting with 500 g of sputum it was possible to isolate 175 mg of each of these two enzymes within 7 to 10 days. Active site titration indicated both enzymes to be at least 97% pure. Disc gel electrophoresis in the presence and absence of SDS and amino acid sequence of the N-terminal region support the conclusion that the elastase and cathepsin G isolated from sputum are identical to the same enzymes isolated directly from the leukocytes of human blood.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Cathepsins / isolation & purification*
  • Chromatography, Affinity / methods
  • Chromatography, Gel / methods
  • Cystic Fibrosis / enzymology*
  • Deoxyribonucleases
  • Electrophoresis, Disc
  • Humans
  • Leukocytes / enzymology
  • Pancreatic Elastase / isolation & purification*
  • Sputum / enzymology*
  • Suppuration


  • Deoxyribonucleases
  • Cathepsins
  • Pancreatic Elastase